Aluminium is highly reactive; its oxide cannot be reduced by carbon. Hall-Héroult process electrolyzes alumina dissolved in molten cryolite (Na₃AlF₆) using carbon anodes.
Explanation:
Ammonium chloride (NH₄Cl) sublimes on heating—it directly converts from solid to vapor without passing through the liquid phase—while common salt (NaCl) remains as a solid residue. This property allows separation by sublimation. Filtration would not work because both are soluble in water, distillation is for liquids, and chromatography separates dissolved substances based on differential adsorption. Lab tip: NH₄Cl vapors condense on the cool funnel to give solid sublimate.
Explanation:
Destructive distillation is the process of heating a carbon-containing substance (like coal or wood) in the absence of air to break it down into various products. For coal, it yields coke, coal tar, coal gas, and coal dust. Fractional distillation is used for separating liquid mixtures like petroleum.
Explanation:
Gypsum (CaSO₄·2H₂O) is added to clinker to control the rapid reaction of tricalcium aluminate with water, which would otherwise cause flash (quick) setting. Gypsum slows down the hydration of C₃A, thus increasing the setting time and allowing workability. Without gypsum, cement would set almost immediately upon mixing with water, making placement impossible.
No comments yet. Be the first to start the discussion!